From: "Michael S. Tsirkin" <mst@redhat.com>
To: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Avi Kivity <avi@redhat.com>,
Marcelo Tosatti <mtosatti@redhat.com>, kvm <kvm@vger.kernel.org>
Subject: Re: [RFC][PATCH] KVM: Introduce direct MSI message injection for in-kernel irqchips
Date: Mon, 24 Oct 2011 19:05:08 +0200 [thread overview]
Message-ID: <20111024170508.GB30385@redhat.com> (raw)
In-Reply-To: <4EA58DF4.2050100@siemens.com>
On Mon, Oct 24, 2011 at 06:10:28PM +0200, Jan Kiszka wrote:
> On 2011-10-24 18:05, Michael S. Tsirkin wrote:
> >> This is what I have in mind:
> >> - devices set PBA bit if MSI message cannot be sent due to mask (*)
> >> - core checks&clears PBA bit on unmask, injects message if bit was set
> >> - devices clear PBA bit if message reason is resolved before unmask (*)
> >
> > OK, but practically, when exactly does the device clear PBA?
>
> Consider a network adapter that signals messages in a RX ring: If the
> corresponding vector is masked while the guest empties the ring, I
> strongly assume that the device is supposed to take back the pending bit
> in that case so that there is no interrupt inject on a later vector
> unmask operation.
>
> Jan
Do you mean virtio here? Do you expect this optimization to give
a significant performance gain?
> --
> Siemens AG, Corporate Technology, CT T DE IT 1
> Corporate Competence Center Embedded Linux
next prev parent reply other threads:[~2011-10-24 17:04 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-10-21 9:19 [RFC][PATCH] KVM: Introduce direct MSI message injection for in-kernel irqchips Jan Kiszka
2011-10-21 9:42 ` Sasha Levin
2011-10-21 11:06 ` Michael S. Tsirkin
2011-10-21 11:51 ` Jan Kiszka
2011-10-21 12:04 ` Michael S. Tsirkin
2011-10-21 13:00 ` Jan Kiszka
2011-10-24 9:45 ` Avi Kivity
2011-10-24 10:19 ` Jan Kiszka
2011-10-24 11:09 ` Avi Kivity
2011-10-24 12:06 ` Jan Kiszka
2011-10-24 12:43 ` Michael S. Tsirkin
2011-10-24 13:11 ` Jan Kiszka
2011-10-24 13:43 ` Jan Kiszka
2011-10-24 14:40 ` Michael S. Tsirkin
2011-10-24 15:00 ` Jan Kiszka
2011-10-24 16:05 ` Michael S. Tsirkin
2011-10-24 16:10 ` Jan Kiszka
2011-10-24 17:05 ` Michael S. Tsirkin [this message]
2011-10-24 17:23 ` Michael S. Tsirkin
2011-10-25 7:24 ` Jan Kiszka
2011-10-25 11:20 ` Michael S. Tsirkin
2011-10-25 11:41 ` Jan Kiszka
2011-10-25 12:05 ` Michael S. Tsirkin
2011-10-25 12:21 ` Jan Kiszka
2011-10-25 13:29 ` Michael S. Tsirkin
2011-10-24 14:25 ` Michael S. Tsirkin
2011-10-25 7:56 ` Avi Kivity
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20111024170508.GB30385@redhat.com \
--to=mst@redhat.com \
--cc=avi@redhat.com \
--cc=jan.kiszka@siemens.com \
--cc=kvm@vger.kernel.org \
--cc=mtosatti@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.